Storms produce a surprising range of phenomena beyond wind and rain, from ghostly lights in the upper atmosphere to animals falling from the sky. Some are rare enough that scientists have only recently confirmed they exist. Here’s what actually happens during severe storms that most people never see or hear about.
Lights Above the Clouds: Sprites, Blue Jets, and Elves
Far above a thunderstorm, the upper atmosphere puts on its own light show. Sprites are short-lived flashes of bright red light that appear between 50 and 90 km altitude, well above the storm clouds themselves. They’re reddish-orange or greenish-blue, with hanging tendrils sometimes called “carrot sprites” and arcing branches above. They last only milliseconds, which is why they weren’t scientifically documented until cameras became sensitive enough to catch them.
Blue jets shoot directly upward from the top of a thunderstorm in a narrow cone, reaching roughly 50 km in altitude and lasting only a fraction of a second. Elves are even stranger: enormous, expanding ring-shaped glows that can stretch up to 400 km in diameter. They form in the ionosphere about 100 km above the ground, triggered by the electromagnetic pulse from a powerful lightning strike below. All three of these phenomena are invisible to most people on the ground, but pilots and high-altitude observers occasionally spot them.
St. Elmo’s Fire and Ball Lightning
When electrical charge builds to extreme levels during a storm, pointed objects like ship masts, airplane wings, and church steeples can begin to glow with a blue or violet luminescence known as St. Elmo’s fire. It’s a type of continuous electrical discharge rather than a single bolt. According to the National Weather Service, lightning may strike the mast within five minutes after it begins to glow, making it both a spectacle and a warning sign.
Ball lightning is far rarer and more mysterious. It appears as a luminous sphere that moves horizontally through the air during or after a thunderstorm. In one of the few scientific recordings, published in Physical Review Letters, researchers captured ball lightning with spectrographs at a distance of 0.9 km and tracked its size, color, and light intensity over its lifetime. The spectral analysis revealed radiation from soil elements throughout its duration, suggesting the phenomenon may involve material swept up from the ground. Despite centuries of eyewitness reports, ball lightning remains poorly understood because it appears so unpredictably.
Fish and Frogs Falling From the Sky
Reports of animals raining down during storms date back to ancient civilizations, and they’re not myths. The most widely accepted explanation involves waterspouts, which are essentially tornadoes over water. A mature waterspout creates a low-pressure central vortex surrounded by a rotating funnel of updrafts, strong enough to vacuum up water and small animals like fish or frogs. When the waterspout moves over land and loses energy, those animals fall back to earth.
The documented cases are vivid. In 1947, a biologist named A.D. Bajkov was eating breakfast at a restaurant in Marksville, Louisiana, when the waitress told him fish were falling from the sky. He walked outside to find fish covering Main Street at a density of roughly one per square yard, with cars and trucks running over them. He collected a jar of specimens and preserved them for museums. When frogs fell in Kansas City in 1873, Scientific American attributed it to a tornado, since there were no nearby bodies of water that could explain their presence. In Dubuque, Iowa, in 1882, small frogs were apparently lifted by a powerful updraft and frozen into hailstones in the cold upper atmosphere.
One detail scientists have noticed is that these animal rains tend to contain creatures of similar size. Objects of similar weight naturally get deposited together as winds lose energy: heavier items fall first, smaller ones drop later.
Why the Sky Turns Green
A sickly green sky before a severe thunderstorm is one of the most unsettling sights in weather, and it’s a real phenomenon with a physical explanation. Normally, air molecules scatter short wavelengths of sunlight (blues and violets) much more effectively than longer wavelengths, which is why the sky appears blue on a clear day. This process is called Rayleigh scattering.
Inside a severe thunderstorm, the cloud contains large quantities of water droplets and possibly growing hail suspended in strong updrafts. Water molecules absorb the long wavelengths (reds and oranges) from sunlight passing through the storm. Meanwhile, Rayleigh scattering removes the shortest wavelengths (blues and violets). With both ends of the visible spectrum diminished, what’s left for your eyes to detect is an excess of green light. The result is a sky that looks noticeably greener than normal, often associated with large hail and intense storms.
Blood Rain
Occasionally, rain falls with a reddish or orange tint, a phenomenon historically called “blood rain.” The explanation is mineral dust. For rain to appear red, relatively high concentrations of iron oxide-rich particles must mix with water droplets inside the cloud. The Sahara Desert is one of the world’s largest sources of airborne mineral dust, and each year massive plumes get carried northward by atmospheric currents. When these dust-laden air masses encounter rain-producing storms over Europe or other regions, the result is precipitation tinted anywhere from pale orange to deep red.
Thundersnow
Lightning during a snowstorm is rare enough that meteorologists sometimes cheer when they witness it. Thundersnow requires a specific and unusual combination of ingredients: abundant moisture, an unstable temperature profile where air cools rapidly with height, a strong lifting mechanism to generate convection, and cold air below freezing level so that precipitation reaches the ground as snow rather than rain. Surface temperatures near 0°C are the most common setup.
The lightning itself forms through the same basic process as in summer thunderstorms. Ice crystals and graupel (small balls of rime ice) collide in a zone between roughly negative 10°C and negative 20°C, separating electrical charge until the voltage difference triggers a discharge. What makes thundersnow so uncommon is that winter atmospheres rarely have enough instability and moisture at the same time to build the tall, vigorous clouds needed for this charge separation to occur.
Birds Trapped in the Eye of a Hurricane
Radar has revealed something remarkable inside hurricanes: birds and insects trapped within the calm eye of the storm. A study from the University of Nebraska-Lincoln examined 33 hurricanes using radar data, looking specifically for “bioscatter” signatures, which are radar returns bouncing back not from rain but from living creatures. Every single one of the 33 hurricanes contained at least some bioscatter.
Stronger hurricanes trapped more birds. The greater the wind speed, the denser and sometimes larger the bioscatter signature became. Hurricanes hitting the Gulf Coast and Florida, where bird populations are larger and more diverse, showed denser signatures on average. The birds are essentially swept into the eye and then unable to escape through the surrounding wall of violent winds. It’s not just native seabirds, either. The radar data suggests land birds and insects get caught up as well, potentially transported hundreds of miles before the storm weakens enough for them to escape.
Infrasound You Can Feel but Not Hear
Severe storms generate sound waves below the threshold of human hearing, at frequencies under 20 Hz. You can’t consciously hear this infrasound, but your body may respond to it. Symptoms associated with infrasound exposure include headaches, difficulty concentrating, dizziness, a feeling of pressure in the ears, drowsiness, and a vague sense of unease or dread. Some people report mood changes and feelings of fatigue or lethargy during and after exposure.
Research has shown that infrasound can even affect the heart. Studies examining frequencies around 10 Hz found changes in cardiac rhythm and reduced force of heart muscle contraction. While the levels produced by natural storms are generally lower than those near industrial machinery, the combination of low-frequency sound with the psychological stress of severe weather may help explain the deep sense of discomfort some people feel during major storms, beyond what the visible conditions alone would suggest.